(2) NIOSH did not identify any evidence from the petitioners or from other resources
that would establish that the class was exposed to radiation during a discrete
incident likely to have involved exceptionally high-level exposures, such as a
nuclear criticality incident, as defined under 42 C.F.R. § 83.13(c)(3)(i).

(3) The Board concurred with the finding of NIOSH that the health of the class may
have been endangered and defined the class according to the 250-work day
requirement specified under 42 C.F.R. § 83.13(c)(3)(ii).

V. _ Effect and Effective Date of Designation

The Secretary submits this report on designation of one additional class to the SEC
for review by Congress, pursuant to 42 U.S.C. §§ 73841(14)(C)(ii) and
7384q(c)(2)(A), as amended by the Ronald W. Reagan National Defense
Authorization Act for Fiscal Year 2005, Pub. L. No. 108-375 (codified as amended in
scattered sections of 42 U.S.C.). Pursuant to 42 U.S.C. § 73841(14)(C)(ii), as
amended by the Ronald W. Reagan National Defense Authorization Act for Fiscal
Year 2005, Pub. L. No. 108-375 (codified as amended in scattered sections of 42
U.S.C.), the designation in this report will become effective 30 days after the date of
this report’s submission to Congress “unless Congress otherwise provides.”

VI. Administrative Review of Designation

The health endangerment determination of the designation provided in this report
may be subject to an administrative review within HHS, pursuant to 42 C.F.R. §
83.18(a). On the basis of such a review, if the Secretary decides to expand the class
of employees covered by this designation, the Secretary would transmit a
supplementary report to Congress providing the expanded employee class definition
and the criteria and findings on which the decision was based.

HHS Special Exposure Cohort Designation:
S-50 Oak Ridge Thermal Diffusion Plant (S-50)


HHS Designation of Additional Members of the
Special Exposure Cohort
under the
Energy Employees Occupational IlIness Compensation Program Act of 2000

Designating a Class of Employees from

S-50 Oak Ridge Thermal Diffusion Plant (S-50)
Oak Ridge, Tennessee

HHS Special Exposure Cohort Designation:
S-50 Oak Ridge Thermal Diffusion Plant (S-50)


I. Designation

I, Michael O. Leavitt, Secretary of Health and Human Services (Secretary), designate
the class of employees defined in Section II of this report for addition to the Special
Exposure Cohort (SEC), as authorized under the Energy Employees Occupational
Illness Compensation Program Act of 2000 (EEOICPA), 42 U.S.C. § 7384q.

NOV - 9 2006 s
\
Date Michael O. Leavitt

II. | Employee Class Definition

Employees of the Department of Energy predecessor agencies and their contractors or
subcontractors who were monitored or should have been monitored while working at
S-50 Oak Ridge Thermal Diffusion Plant (S-50) for a number of work days
aggregating at least 250 work days during the period from J uly 9, 1944 through
December 31, 1951, or in combination with work days within the parameters
established for one or more other classes of employees in the SEC.

Ill. Designation Criteria and Recommendations

Pursuant to 42 U.S.C. § 7384q, for the class defined in Section II of this report, the
Secretary has determined, and the Advisory Board on Radiation and Worker Health
(Board) has recommended, that
(1) it is not feasible to estimate with sufficient accuracy the radiation dose that the
class received; and
(2) there is a reasonable likelihood that such radiation dose may have endangered
the health of members of the class.

The SEC final rule states in 42 C.F.R. § 83.13(c)(1) that it is feasible in two situations
to estimate the radiation dose that the class received with sufficient accuracy. First,
the rule states that radiation doses may be estimated with sufficient accuracy if
NIOSH has established that it has access to sufficient information to estimate the
maximum radiation dose for every type of cancer for which radiation doses are
reconstructed that could have been incurred under plausible circumstances by any
member of the class. Alternatively, radiation doses may be estimated with sufficient
accuracy if NIOSH has established that it has access to sufficient information to
estimate the radiation doses of members of the class more precisely than a maximum
dose estimate.

The Board, pursuant to 42 U.S.C. § 7384q, advised the Secretary to designate the
class as an addition to the SEC in a letter received by the Secretary on October 12,
2006.

HHS Special Exposure Cohort Designation:
S-50 Oak Ridge Thermal Diffusion Plant (S-50)


IV. Designation Findings

Feasibility of Estimating Radiation Doses with Sufficient Accuracy

The Secretary established the feasibility determination for the class of employees
covered by this report upon the findings summarized below.

(1) During the period of the proposed class, employees at S-50 either were involved
with wartime uranium enrichment operations using the liquid thermal diffusion
process or participated in postwar activities associated with the Nuclear Energy
for the Propulsion of Aircraft (NEPA) project.

(2) NIOSH determined that it lacks internal and external personnel dosimetry data,
other workplace monitoring data, and process and radiological source information
to reconstruct with sufficient accuracy the internal and external exposures to
uranium compounds and other unknown radioactive materials that may have been
present at S-50 from July 9, 1944 through December 31, 1951.

(3) Members of the class may have received radiation exposures from uranium
compounds and other unknown radioactive materials that may have been present
at the plant.

(4) Pursuant to 42 C.F.R. § 83.13(c)(1), NIOSH determined that there is insufficient
information either to estimate the maximum radiation dose for every type of
cancer for which radiation doses are reconstructed that could have been incurred
under plausible circumstances by any member of the class, or to estimate the
radiation doses of members of the class more precisely than a maximum dose
estimate.

(5) NIOSH determined that it is possible to reconstruct or bound occupational
medical doses.

Health Endangerment

The Secretary established the health endangerment determination for the class of
employees covered by this report upon the findings summarized below.

(1) Pursuant to 42 C.F.R. § 83.13(c)(3), NIOSH established that there is a reasonable
likelihood that such radiation doses may have endangered the health of members
of the class. Pursuant to 42 C.F.R. § 83.13(c)(3)(ii), NIOSH specified a minimum
duration of employment to satisfy this health endangerment criterion as “having
been employed for a number of work days aggregating at least 250 work days
within the parameters established for this class or in combination with work days
within the parameters (excluding aggregate work day requirements) established
for one or more other classes of employees in the Cohort.”

HHS Special Exposure Cohort Designation:
S-50 Oak Ridge Thermal Diffusion Plant (S-50)